The reports of the Intergovernmental Panel on Climate Change (IPCC) highlight how human activities have affected global temperature in the past 50 years. An overwhelming majority (97%) of climate scientists now accept these findings.
For information on how you can help to reduce carbon dioxide emissions (also known as your 'carbon footprint') please visit the section Act Now.
Here are some key human activities that contribute to climate change.
- Burning of fossil (mineral) fuels
- This tops the list of human activities that contribute to increased levels of greenhouse gases in the atmosphere. Fossil fuels such as petroleum, natural gas (e.g. methane) and coal constitute major energy sources for industries, transport and heating in our homes. It is estimated that burning of fuels world-wide produces around 21.3 billion tons (21.3 gigatons) of carbon dioxide every year. Part of the carbon dioxide released when fossil fuels are burned is absorbed naturally by plants and oceans, but the rest gets caught up in the atmosphere and causes global warming.
- Poor use of land
- Poor land use is directly linked to climate change partly because, when soil and vegetation are lost, more carbon dioxide is released into atmosphere and less can be absorbed, which results in further global warming.
- Examples of poor use of land include urban sprawl (uncontrolled urban development), destruction of forests and excessive farming.
- Waste disposal
- If waste is not properly treated or disposed of, it produces greenhouse gases such as methane and carbon dioxide. These gases contribute to global warming. Disposal of waste by landfill is a key source of man-made methane emissions in the atmosphere. This is one reason why it is so important to reduce waste or recycle it.
- Cooling units and aerosol sprays
- When the use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) in aerosol sprays and as coolants in fridges, freezers and air conditioners was phased out in order to prevent ozone layer depletion, CFCs and HCFCs were replaced with hydrofluorocarbons (HFCs). The use of HFCs is restricted in the UK as they also contribute to global warming.